A vast archive of raw census microdata covering Eurasia in the period since 1960 survives in machine- readable form. Over the past five years, this project has made a substantial portion of these data available to researchers for the first time. This proposal seeks continued funding to preserve, integrate, and freely disseminate large-scale Eurasian population microdata samples. The first phase of the project, focusing on European data, is on schedule to accomplish all the goals described in our original application. The primary goal was processing data and documentation to create publicly-accessible large-scale census microdata samples from multiple decades for a wide range of European countries and disseminating those data to researchers. This work involved data cleaning, drawing samples, implementing confidentiality protections, creating integrated variables, developing comprehensive metadata, and disseminating the data and metadata through a sophisticated web-based access system. This competing continuation project will extend the geographic scope eastward to cover Asia, prepare 40 additional census microdata samples for release to the research community, improve the geographic variables in the database, and recover data at risk of destruction. In addition to adding new partner countries, the expansion of the database will add new samples from the 2010 round of censuses for countries already incorporated into the integrated data series, and increase the size of several existing samples. The project leverages previous federal investments in social science infrastructure. Grants from the National Institutes of Health and the National Science Foundation laid the groundwork for the project by funding many of the fixed costs. Those projects underwrote the development of data cleaning and sampling procedures, metadata systems, data conversion and dissemination software, and design protocols for data and documentation. Raw microdata files, internal documentation, and redistribution agreements for most censuses to be processed have already been obtained. As a result, this project is highly cost-effective. The integrated database provides fundamental infrastructure for scientific research, education, and policy- making. The new data will allow social scientists to make comparisons across Europe and Asia during five decades of transformative change, and will result in a substantial body of new research on population health, economic development, fertility and mortality decline, population aging, migration, and reshaping of families. By opening new avenues for investigating the causes and consequences of population dynamics, this infrastructure directly addresses the priorities of the Demographic and Behavioral Sciences Branch of NICHD.